Bangerter Highway 4 Interchanges (114th, 90th, 70th, and 54th) Design‐Build

Bangerter Highway is a major north‐south corridor located along the rapidly growing west side of the Salt Lake Valley. Currently, the road moves an average of 58,000 vehicles per day, a number that is expected to double by 2040. At‐grade intersections contribute to excessive delays during peak hours and add to the risk of accidents occurring.

As part of a program to convert the corridor into a freeway, the Utah Department of Transportation (UDOT) replaced all at‐grade intersections with grade‐separated interchanges to meet the area’s current and future transportation needs. As a design subconsultant, Lochner was responsible for the design of two of the four interchanges (7000 South and 9000 South) constructed during this project.

Due to limited right of way, both the 7000 South and 9000 South interchanges were designed as single‐point urban interchanges (SPUI). Because the contract was awarded in January, the Lochner team had to meet a significantly accelerated schedule to allow the 7000 South interchange to be operational by the deadline, Thanksgiving of the same year.

Several challenges were presented during the design of these interchanges. High traffic volumes in the corridor required innovative solutions to maintain traffic flow through the intersections during construction. Maintenance of traffic phasing for both locations included building the interchange ramps first while keeping six lanes operational. At 7000 South, displaced left‐turn lanes were used to maintain required turn movements and storage lengths in the available space.

The Jordan Aqueduct, a 72‐ to 78‐inch pipeline that supplies water to much of the west side of the Salt Lake Valley, is located adjacent to both the 7000 South and 9000 South interchanges and is very sensitive to additional loading, settlement, and vibrations. To meet the requirements for construction in the aqueduct easement, the design team developed a shallow sign foundation to reduce impacts from these permanent structures. The design team also coordinated extensively with the Jordan Valley Water Conservancy District and the United States Bureau of Reclamation during the design phase, allowing the agencies to review the features that would be permanently located in the easement to ensure impacts were avoided. The team also worked closely with West Jordan City and third‐party utilities—including power, gas, and communications providers—to relocate utilities away from construction activities to facilitate construction on an accelerated schedule.

The existing conveyance pipe for Bingham Creek at 9000 South posed another challenge. The pipe, due to its age and condition, was initially considered for replacement, which would have caused substantial lane closures. To avoid impacting traffic, the design team slip lined a portion of the pipe in lieu of replacement. This approach restored the pipe’s flow capacity, increased its life span, accelerated the pipe’s construction, and avoided lane closures to the 9000 South Roadway.